The present invention relates to a process for producing relief copies, in which a light-hardenable copying material comprising a light-sensitive layer which contains a photopolymerizable mixture, a photodimerizable polymeric compound or a negative-acting light-sensitive diazo compound, is exposed imagewise, and the unexposed areas of the layer are thereafter washed away by a developer.
In most cases, such light-hardenable materials, particularly photopolymerizable materials, are not yet fully hardened after exposure to the light image. It has been found that, depending on the time interval between exposure and development, there are distinct differences in the wedge length of copied continuous tone step wedges. These variations are particularly pronounced in cases of exposure with laser light, for example from an argon ion laser.
U.S. patent application Ser. No. 323,050, filed Nov. 19, 1981, now abandoned, discloses one process whereby these disadvantages can be avoided comprising warming the light-sensitive material, during or after exposure, for a short time at an elevated temperature and then developing.